People who've peered into the less well-known corners of the NES's library and seen a few pictures from this game will generally know it as a Castlevania knockoff, and that's certainly the first impression it gives: the protagonist (Mr. Eyes?) has the same lanky build, and he walks and jerkily leaps across floors built out of cubes, and connected by long inconvenient staircases.

#2: ...but there's so much more!

...2 Player?

Like Bionic Commando, DuckTails and Mickey Mousecapade before it, this game appears to be a platformer, but its gimmick factors rather heavily on the gameplay. In this case (rather than having a bionic arm, weird pogo/golf attack, or a "mirror player" to keep alive), Mr. Eyes is a falconer, and his falcon Cutrus is a somewhat-integral part of the game:

You can either play "2PLAY" mode, and have your friend control the flighty and feeble bird,

Or you can do standard "1PLAY" mode, and issue orders to your feathered friend:

UP + B: Fly around in a zig-zag pattern!

UP + B (while he's flying): Come back and sit on my arm!

DOWN + B (while he's flying): Do a barrel roll diving swoop attack!

Mostly Cutrus is good for poking a few "door opening" buttons, or pecking away at the walls to reveal power-ups that you can't reach. Also when he's flying around separate, he's a small enough target on an erratic enough pattern that he doesn't tend to take a lot of damage (and he's got his own energy bar, so his potential clumsiness won't cost you your life).

In fact, the only time I found the bird died before Mr. Eyes was during the game's boss fights, when I was trying to use him for some distance-sniping on the game's bulky and damage-resistant bosses.

Oh, and about those bosses, and their stages?

#3: Well, Castlevania isn't the ONLY franchise they're ripping off:

Perhaps they should have called the game, Mega-Eyes

Yup, it's a level hub game: you can start with any of the first 7 stages, but you must complete them all to play the 8th. The stages definitely have different looks, and some of them involve some fun exploring and "puzzle" mechanics to find your way through or not wander around in circles.

But eventually your goal in each stage is to find the boss. And the boss fights are really hard.

If you beat the boss, you and your former foe are served high tea by a skeleton waiter, and the game shows you a password and the cryptic message, "You have earned a more powerful sword".

There's nothing in-game to tell you what "a more powerful sword" means. The enemies you fight in the next level are not easier to defeat because of its vague "power". In fact, you have to resort to a FAQ to find out how your sword has been made "more powerful", and it's both confusing and frustrating:

Each boss's "more powerful sword" will make your sword do more damage to ONE SPECIFIC OTHER BOSS.

Without trial and error (or a good FAQ), there's no way to know how this will work. Moreover, if you beat Boss X and get the sword that's strong against Boss Y...but you happen to kill Boss Z next, there's no way to get your strong-against-Boss-Y blade back.

It's hard to imagine what the designers were going for; its possible that the bosses are SO difficult that they thought you'd only be able to win by finding the weakest boss first (the one that you are most likely to beat without a More Powerful Sword), and then you could play all the other 5 remaining stages, and the only boss you'd manage to beat next would be the one you're now More Powerful against, etc.

#4: But I think the easiest way to show the wrong-headedness of this mechanic...

...is to compare it to the franchise it's ripping off. How popular would Mega Man be if its "stage select" was designed like 8 Eyes:

Pick a stage!

Win, and get a cryptic victory message!

Then, without being given any sense of how you've powered-up,

try to figure out which stage you should fight next!

and keep in mind, if you pick the wrong stage, you're almost guaranteed to die on the boss fight...have fun!